During otoacoustic emissions suppression, the stimulus is alternated between a masking white noise signal and a click signal; where the recordings are acquired in response to the click stimulus. By comparing a suppressed transient OAE recording to one that is acquired normally, conclusions can be drawn about the workings of the efferent nerve fibers and the suppression of sound. The suppression noise masking addon for SmartTrOAE is available for the Duet and USB hardware platforms.